Identification of crucial LncRNAs associated with testicular development and LOC108635509 as a potential regulator in black goat spermatogenesis

The establishment and maintenance of spermatogenesis is a complex process involving a vast of regulatory pathways. There is growing evidence revealing that long noncoding RNAs (lncRNA) play important roles in regulating testicular development and spermatogenesis in a stage-specific way. However, our understanding of how lncRNA regulates testicular development and spermatogenesis in black goats is quite limited. In the current study, we screened the transcriptomes (lncRNA and mRNA) of testicular from Guangxi black goats before puberty (3 days old, D3; 30 days old, D30), puberty (90 days old, D90) and postpuberty (180 days old, D180), in order to identify the lncRNA interaction with mRNAs contributes to goat spermatogenesis. The RNA-sequencing (RNA-seq) analysis showed that there were 1211, 12,180, 834 differential lncRNAs and 1196, 8838,269 differential mRNAs at the ages of D30 vs. D3, D90 vs. D30, and D180 vs. D90. The lncRNAs showed the most significantly changes from D30 to D90, which indicated that D90 was a key node of lncRNAs participated in the regulation of testicular development and spermatogenesis in black goat. According to functional enrichment analysis of GO and KEGG, we found that differentially expressed lncRNAs (DE lncRNAs) and their target genes regulated spermatogenesis through signal pathways including MAPK, Ras, and PI3K-Akt. Using cis- and trans-acting, 39 DE lncRNAs-targeted genes were found to be enriched for male reproduction. Of these, LOC108635509, which specific expressed in testis and upregulated the expression levels at D90, was found participated in the regulation of testicular development through promoting the proliferation of Sertoli cells (SCs). Overall, this study provides new insight into the regulatory mechanisms that support spermatogenesis and testicular development in black goats.